Polyarylene sulfide resin is an engineering plastic having excellent chemical resistance, heat resistance and mechanical properties. Therefore, the polyarylene sulfide resin is widely used in electric and electronic parts, vehicle-related parts, aircraft parts and housing equipment parts. As electronic equipment products such as digital cameras and tablets are becoming smaller in size, product housings in use are becoming thinner. Further, in the field of vehicle-related parts such as auto parts, vehicles are becoming lighter in weight for energy saving.
To reduce the thicknesses and weights of products for these applications, studies on shift from metal materials to resin materials are under way.
For resin materials which will become substitutes for metal materials, strength, heat resistance and chemical resistance are required. In addition, an electromagnetic shielding effect capable of suppressing the malfunction of peripheral equipment caused by electromagnetic waves produced during communication with a portable terminal or during the driving of an automobile and also the influence upon human bodies of the electromagnetic waves are required.
Although the polyarylene sulfide resin has excellent heat resistance and chemical resistance, it is insulating and therefore has low conductivity and unsatisfactory mechanical strength. To solve this problem, Patent Document 1 proposes a resin composition comprising a polyarylene sulfide resin and carbon fibers. However, this resin composition is unsatisfactory as it does not meet the requirements for both mechanical strength and electromagnetic shielding effect.
For resin materials which will become substitutes for metal materials for use in the bearings of gears, slidability and impact strength are required. Although the polyarylene sulfide resin has higher slidability than other resins, it is unsatisfactory in terms of slidability and impact strength when it is used for these applications. To solve this problem, Patent Document 2 proposes a resin composition comprising a polyarylene sulfide resin and wholly aromatic polyamide fibers. However, this resin composition is unsatisfactory as it does not meet the requirements for both slidability and impact strength. Patent Document 3 proposes a resin composition comprising a polyphenylene sulfide resin, wholly aromatic polyamide fibers and stainless flakes. Since this resin composition comprises a filler except for the wholly aromatic polyamide fibers, it does not meet the requirement for impact strength.
Patent Document 4 proposes a resin composition comprising a polyarylene sulfide resin and glass fibers. However, the resin composition of this document is unsatisfactory as it does not meet the requirements for both mechanical strength and moist heat resistance.
Meanwhile, Patent Documents 5 and 6 disclose a process for producing polyarylene sulfide by reacting a diiodo aromatic compound, a sulfur compound and a polymerization terminator. Patent Document 5 discloses diphenyl disulfide as a polymerization terminator. Patent Document 6 discloses diphenyl sulfide as a polymerization terminator.    (Patent Document 1) JP-A 56-135549    (Patent Document 2) JP-A 56-4654    (Patent Document 3) JP-A 06-116495    (Patent Document 4) JP-A 06-220322    (Patent Document 5) JP-A 2012-513492    (Patent Document 6) JP-A 2013-518933